1. Field of the Invention
The present invention relates to an insulating device for an electrochemical energy storage unit and to a method for producing an insulating device for an electrochemical energy storage unit.
2. Description of the Background Art
In the case of batteries for hybrid and electric vehicles, a large number of galvanic cells are connected in series to achieve a higher voltage. Such batteries can be called electrochemical energy storage cells, whereby accumulators, also used in hybrid and electric vehicles, can be understood as covered by this term as well. Because of the high currents which then flow through such electrochemical energy storage cells and the resulting high heat, cooling of the electrochemical energy storage cells is needed in addition.
In the conventional art, there are various cooling options for such problems such as, for example, air cooling, liquid cooling, direct cooling via an air conditioning unit (AC=air conditioning), and possibly also combinations thereof.
The cooling can be thermally connected via surfaces of the electrochemical energy storage cells or via thermal arresters, as is disclosed, for example, in the patent publications WO 2009/006998 A1 or in EP 2 026 387 A1. A principal approach for connecting a cooling plate to a contact bar according to the state of the art is furthermore shown in FIG. 1. In this case, rivet pins 1 as the retaining member are guided through an opening of cooling plate 2 and at least one contact bar 4, whereby cooling plate 2 is electrically insulated from contact bars 4 by a thermally conductive film 3.
It is problematic in the solutions according to the conventional art, however, that the air cooling requires considerable installation space and such air cooling has limitations further also with respect to possible soiling and thermal dissipation performance. When the cells are connected via the surfaces of the cooling plate, the thermal resistances worsen the heat transfer and thereby the heat dissipation rate. Cooling of arresters makes it possible to remove heat directly from the cells, but in the case of a cooling approach of this kind reliable electrical insulation should be assured. At the same time, the thermal connection should be as good as possible; i.e., there should be as low a thermal resistance as possible between contact bar 4 and cooling plate 2.